Solar cell and photovoltaic module

Abstract

A solar cell and a photovoltaic module. The solar cell includes: a substrate including a front surface and a back surface, a tunneling layer formed on the back surface of the substrate, a doped conductive layer formed on the tunneling layer, an intrinsic polycrystalline silicon layer formed on the doped conductive layer, a first passivation layer formed on the intrinsic polycrystalline silicon layer, and a first electrode formed on the first passivation layer. The first electrode is in contact with the intrinsic polycrystalline silicon layer by running through the first passivation layer and is spaced apart from the tunneling layer. The photovoltaic module includes the solar cell.

What is claimed is: 
     
         1 . A solar cell, comprising:
 a substrate including a front surface and a back surface;   a tunneling layer formed on the back surface of the substrate;   a doped conductive layer formed on the tunneling layer;   an intrinsic polycrystalline silicon layer formed on the doped conductive layer;   a first passivation layer formed on the intrinsic polycrystalline silicon layer; and   a first electrode formed on the first passivation layer,   wherein the first electrode is in contact with the intrinsic polycrystalline silicon layer by running through the first passivation layer and is spaced apart from the tunneling layer,   wherein the intrinsic polycrystalline silicon layer is selectively formed between the first electrode and the doped conductive layer, and   wherein the first passivation layer includes a first part covering the intrinsic polycrystalline silicon layer and a second part in direct contact with the doped conductive layer.   
     
     
         2 . The solar cell according to  claim 1 , wherein, in a plan view, an orthographic projection of the first electrode is within an orthographic projection of the intrinsic polycrystalline silicon layer. 
     
     
         3 . The solar cell according to  claim 1 , wherein a thickness of the doped conductive layer ranges from 10 nm to 80 nm, and a thickness of the intrinsic polycrystalline silicon layer ranges from 10 nm to 80 nm. 
     
     
         4 . The solar cell according to  claim 1 , wherein the first electrode comprises a body portion, a first extension portion, and a second extension portion,
 the body portion has a substantially flat interface with the intrinsic polycrystalline silicon layer, the first extension portion protrudes from the body portion, and the second extension portion is spaced apart from the body portion and the first extension portion.   
     
     
         5 . The solar cell according to  claim 4 , wherein the first extension portion protrudes into the doped conductive layer. 
     
     
         6 . The solar cell according to  claim 4 , further comprising a first local doped region and a second local doped region, wherein the first extension portion is coated by the first local doped region, and the second extension portion is coated by the second local doped region. 
     
     
         7 . The solar cell according to  claim 1 , further comprising local doped regions, wherein each local doped region is connected to one or more of the first electrode, the intrinsic polycrystalline silicon layer, and the doped conductive layer, and the first electrode is electrically connected to the doped conductive layer through the local doped regions. 
     
     
         8 . The solar cell according to  claim 7 , wherein a concentration of impurities of a first conductivity type in the local doped regions is less than a concentration of impurities of the first conductivity type in the doped conductive layer. 
     
     
         9 . The solar cell according to  claim 1 , further comprising:
 an emitter formed on the front surface;   a second passivation layer formed on the emitter; and   a second electrode, wherein the second electrode is in contact with the emitter by running through the second passivation layer,   wherein the substrate and the doped conductive layer are doped with impurities of a first conductivity type, and the emitter is doped with impurities of a second conductivity type opposite to the first conductivity type.   
     
     
         10 . The solar cell according to  claim 9 , wherein the front surface of the substrate and the emitter are textured, and the back surface of the substrate is not textured. 
     
     
         11 . The solar cell according to  claim 10 , wherein the second passivation layer is textured. 
     
     
         12 . The solar cell according to  claim 1 , wherein the first electrode does not run through the intrinsic polycrystalline silicon layer. 
     
     
         13 . A photovoltaic module, comprising:
 a solar cell string comprising a plurality of solar cells;   a front packaging layer covering a front surface of the solar cell string;   a back packaging layer covering a back surface of the solar cell string;   a front cover plate covering the front packaging layer; and   a back cover plate covering the back packaging layer,   wherein at least one of the plurality of solar cells includes:
 a substrate including a front surface and a back surface; 
 a tunneling layer formed on the back surface of the substrate; 
 a doped conductive layer formed on the tunneling layer; 
 an intrinsic polycrystalline silicon layer formed on the doped conductive layer; 
 a first passivation layer formed on the intrinsic polycrystalline silicon layer; and 
 a first electrode formed on the first passivation layer, 
   wherein the first electrode is in contact with the intrinsic polycrystalline silicon layer by running through the first passivation layer and is spaced apart from the tunneling layer,   wherein the intrinsic polycrystalline silicon layer is selectively formed between the first electrode and the doped conductive layer, and   wherein the first passivation layer includes a first part covering the intrinsic polycrystalline silicon layer and a second part in direct contact with the doped conductive layer.